Bonnie Modugno, MS, RD - Weight Is Not a Good Measure of Obesity
Researchers and scientists are saying it out loud. Weight is not a good marker of obesity or health. When we will stop using weight as a surrogate for our health status?
I attended theAmerican Society for Nutrition conference two weeks ago in San Francisco. After the last presentation of the conference I stood at the microphone available to the attendees and asked just this question. One of the presenters started clapping his hands. I heard applause behind me.
Yesterday I was looking for information about endocrine function and persistent organic pollutants. These are the studies linking chemical elements in our water, soil, air and food with hormonal dysfunction. I caught one slide in one of the presentations. “Weight is not a good measure of obesity,”
UNDUE FOCUS ON WEIGHT
Weight is measured in research, in clinical practice and community health centers. Weight is a key indicator in public health records and statistics. Weight is monitored at schools, at gyms and other fitness facilities, and in too many homes. It as if there is collective will for weight to be the concrete determinant of health if only because it is so easy and cheap to measure.
Weight is assumed to be a significant marker determining whether one is healthy or not. BMI is blindly used to determine who is overweight, who is obese and who gets bariatric surgery. Despite its flaws, weight and height along with its cousin, the BMI index, have been given far too much credibility. So if not weight, what else?
MORE ACCURATE BIOMARKERS OF DISEASE RISK
Maybe we all need to focus on the actual bio-markers of health and disease. Clinicians already measure blood pressure regularly. Blood glucose is often included in standard laboratory blood tests, but we need to pay attention to slow gradual increases, not just whether someone is diabetic or not.
We need to pay more attention to better markers of cardiovascular disease risk. Total cholesterol and LDL cholesterol predict less than 50% of risk. We are preoccupied with these numbers. Drug companies have products to lower these numbers. But that doesn’t mean these are the best indicators of risk.
Small dense LDL, elevated triglycerides and depressed HDL-cholesterol are proving to be much more effective bio-markers for risk. Small, dense LDL is typically indicated with lower HDL levels (less than 40mg/dl for men, 50 mg/dl for women) and higher triglyceride levels (greater than 150 mg/dl).
It may be simpler still to focus on how the body gains weight. Central body fat distribution–the apple shape–is more problematic. For years clinicians have been encouraged to measure waist:hip ratio. A ratio of >0.9 is considered higher risk for men; a ratio of >0.8 considered a higher risk for women.
AN ALTERNATIVE TO WEIGHT/HEIGHT RATIOS AND THE BMI
Today, an alternative to BMI is being introduced, theBAI–Body Adiposity Index. BAI is a measure that purports to assess body adiposity, not merely weight and height ratios. The BAI index is a complex ratio of weight to hip circumference. It’s a start.
There is still too much attention to weight, but at least BAI begins to focus on where the weight is stored. We have a long way to go before we drop our preoccupation with weight. The sooner we do, the sooner we can focus on the behaviors that truly make a difference in our health status.
BEYOND BIO-MARKERS: LOOKING AT BEHAVIOR
We need to start focusing on what lifestyle behaviors contribute to elevated glucose levels, dyslipidemia seen with low HDL-C and elevated triglycerides, and elevated blood pressure and what behavior changes those numbers. Weight isn’t necessarily cause the cause of these problems. Often these bio markers are off because of the metabolic process that increases weight. Too often weight is the result of the problem.
It is time for lifestyle factors to get more attention and more respect in the research and health care community. Diet, activity, stress management, medication management are all viable behaviors that deserve attention, monitoring, and support. Continuing to focus on weight distorts our perception of health and diverts our attention from the lifestyle factors that can make a real difference in health status and quality of life.